US Patent 10544797 Propeller fan, fluid feeder, electric fan, and molding die

A propeller fan includes a boss hub portion and a blade including a front edge portion, a rear edge portion, and an outer edge portion. The outer edge portion has a front outer edge portion, a rear outer edge portion, and a connection portion connecting the front outer edge portion and the rear outer edge portion to each other. In a plan view of the blade along a central axis, a maximum radius R1max of the outer edge portion in a portion corresponding to the front outer edge portion and a maximum radius R2max of the outer edge portion in a portion corresponding to the rear outer edge portion satisfy a condition of R1max>R2max. With such a construction, a propeller fan which generates wind less in pressure fluctuation and is capable of sending comfortable wind and achieving lowering in noise is provided.